UT_ANALOG_IN — Analog input (scale, NAMUR NE43, filter, quality, simulate)

Turns a raw analog reading into engineering units. It detects a failed transmitter
or a wire break (NAMUR NE43 bands for 4–20 mA), filters noise, reports quality,
and decides what value to give when the signal is bad.

Pins

Record UT_ANALOG_DATA

NE43 bands (UT_AI_4_20MA):

The mA thresholds are computed from rawMin/rawMax, so any card scaling works
(0–27648 for 4–20 mA: fail low at −691.2 counts, fail high at 29376).
UT_AI_0_20MA and UT_AI_0_10V have no fail bands (a wire break reads as 0): below
0 % or above 100 % is UNCERTAIN. UT_AI_CUSTOM is the same plus fail bands at
customLowFail / customHighFail.

How it works

• A failure (a fail band, or a NaN / infinite reading) must last faultDelay.
  Meanwhile the value is held at the last good one and the quality is UNCERTAIN,
  so a short spike does nothing. After the delay it is a Fault (a
  UT_PROTECT trip with faultReset / recover), quality BAD, and
  faultAction gives the value. Each fault is counted in faults.
• The filter is exact at any scan rate and stops while the signal has failed, so
  HOLD gives the last good filtered value.
• A zero or invalid span is BAD at once with wrnConfig; it is not counted as a
  signal failure. Value and Percent are never NaN or infinity.
• Simulate: Value = simValue, quality SIM, failures are not checked.
• Zero trim: trimOffset corrects a transmitter that reads a little off in the
  field (e.g. −0.02 m on a level that shows 0.02 m with the well empty). It is added
  to the scaled reading, so the clamp still holds Value inside the range.
• Second unit: valueAlt follows Value (also while held or simulated). Unset
  (altFactor 1, altOffset 0) it equals Value. A trim, factor or offset that is
  not a number or infinite sets wrnConfig and is not used (trim 0, valueAlt 0);
  the quality is not affected.
• Power cut: nothing is kept. faults starts at 0, a MANUAL fault is forgotten,
  and a signal that is still failed faults again after faultDelay.

Using it

LevelCfg.rawMax := 27648.0;  LevelCfg.engMax := 5.0;   (* 0..5 m: the HMI shows the unit *)
Level(In := INT_TO_REAL(%IW0), Data := LevelCfg);